Heating means



Jan. 31, 1939. E. L, WIEGAND ET AL 2,145,564

HEATING MEANS Filed NOV. 12. 1935 2 Sheets-Sheet Edwin 'L- wicgqnd. ni Ernest N- Guinean,

I N VI'LNTORS ATTORNLY Jan. 31, 1939. E. 1.. WIEGAND. Er AL' 2,145,564

HEATING MEANS v Filed Nov. 12, 1955 2 Sheets-Sheet 2 Edwin L wiegand.

AT TORNT5 Patented Jan. 31, 1939 UNITED STATES HEATING MEANS Edwin L. Wiegand and Ernest N. Calhoun, Pittsburgh, Pa., assignors, by mesne assignments,

to Edwin L. Wiegand, Pittsburgh, Pa.

Application November 12, 1935, Serial No. 49,368

7 Claims.

Our invention relates to heating means, and more particularly to the electrical resistance type of heating units, and the principal object of our invention is to provide a new and improved heating means of this type.

In the drawings accompanying this specification, and forming a part of this application, we have shown, for purposes of illustration, one form which our invention may assume, and in these drawings:

Figure 1 is a top plan view of the embodiment of our invention, illustrating adjoining parts of cooperating members fragmentarily,

Figure 2 is a bottom plan view of the embodiment shown in Figure 1,-some parts having been omitted and some broken away to better fit the view to the sheet,

Figure 3 is a sectional view corresponding to the broken line 33 of Figure 1, I

- Figure 4 is a perspective view of a detail,

Figure 5 is an enlarged fragmentary sectional 'view corresponding to the line 55 of Figure 1,

Figure 6 is an enlarged disassembled fragmentary perspective view showing a connection means, and

Figure 7 is a diagrammatic view'illustrating a manner of electrical connection.

The embodiment of our invention herein disclosed comprises a heating source, here shown to be an electric heating element I 0, adapted to cooperate with adapter means I I, the latter means adapting the heating unit III for placement within a recess I2, such as an aperture formed in a stove surface I3, in a manner as suggested in Figure 3.

The heating unit I comprises a. support I4, and as here shown, the support may be a discshaped piece of electric and heat insulating material of substantial thickness; one material which is preferably used is porcelain.

As best shown in Figure 3, one flat surface I of the support I4 is provided with a series of grooves extending into the thickness of the support a considerable distance. The grooves are 45 preferably spiral-shaped, starting from the center of the support I4 and working toward the .pe-. riphery thereof. As disclosed in Figure 1, two spiral grooves I6 and II are formed in the surface I5 of the support I4, the spiral grooves I6 and I1 starting adjacent the center of the support I4, with the inner portions thereof substantially diametrically opposed, and working outwardly, in an intercalated manner, the extremities thereof also being preferably diametrically opposed, as shown at I8 and I9.

The central portion of the support I4 may be recessed, as shown at 20, to a level corresponding to the recessed surface of the grooves I6 and I1, and at this central portion a terminal receiving means 2I may be positioned. Terminal receiving means 22 and 23 are also preferably disposed respectively adjacent the ends l8, l9, of the grooves 16, ll, the terminals 22, 23 being similar in construction to the center terminal 2|. Disposed within the grooves I6, I! are heating means, preferably comprising helical coils 24 and 25, of any well known electrical resistance wire. It will be appreciated, however, that the heating means may take the form of any other well known heat producing .SOLLICB. Also, and with particular reference to the electric-resistance type of heating element, the helical coils 24, 25 may be replaced by a strip of resistance material, bent zig-zag or any other shape, or possibly a plain resistance wire or strip, and this resistance material disposed in the grooves to assume the configuration thereof.

As best shown in Figure 1, the helical coil 24 is disposed within the channel formed by the groove I6, and necessarily assumes the spiral shape of the groove. The helical coil 25 is in like manner disposed within the groove I'I. As shown in Figures 1 and 3, the helical coils 24, 25 are of a lesser diameter than the width of the respective grooves I6, IT, to facilitate the assembly of the coils with the grooves, and also to permit differential expansion between the coils and the support I4. To hold the coils 24, 25 in operative position, the grooves I6 and I! are provided with a plurality of abutments 26, adjacent the outermost part of the walls thereof, the abutments 26 overhanging the coils 24, 25, and tending to hold these "coils in position in their'respective grooves.

The inner extremities of the coils 24', 25 are respectively passed through apertures 21 and 28, formed in the recessed central portion 20 of the support I4, and the extremities extend through to the opposite surface of the support, and are secured to the center terminal-receiving means 2I, As best shown in Figure 3, the center terminal 2I preferably comprises a machine screw 29, having its head engaging the adjacent surface of the recessed portion 20, and its screw-threaded shank passing through a central aperture in the support I4, and projecting away from the opposite surface of the support. A nut 30 engages the screw-threaded shank of the screw 29 and draws this screw up tightly in position with respect to the support I4. The extremity of the coils 24,

25 are then wound around the screw 28 and a Washer is interposed between the winding of each extremity. A nut 3| isthen screwed onto the shank of the screw 29 to mechanically and electrically hold the inner extremities of the coils 24, 25 assembled with the center terminal 2|.

The outer extremities of the coils 24, 25 are fastened to the respective terminals 22,23 in a similar manner, only the terminal 22 being shown in detail, and a description of this connection will suffice. The terminal 22 comprises a machine screw 32, having its head disposed adjacent the portion l8 of the groove l6, the head thereof bearing against the bottom of the groove and the screw-threaded shank passing through an aperture in the support l4 and extending away from the opposite surface of the support. A nut 33 engages the. screw-threaded shank and the adjacent surface of the support to firmly hold the screw 32 in position. The outer extremity of the coil 24 is then wound around the shank, and'a washer and a nut 34, are positioned on the shank to hold the extremity of the coil mechanically and electrically to the terminal 22.

.Conducting strips 35, 36, and 31, each having one end respectively engaging the terminals 2|, 22, and 23 are provided to connect these terminals to a suitable source of energy. The other end of the conducting strips lead to a point within a connection block 38, the latter preferably being formed of the same material as the support I4, and the block is floatingly held in position by its connection with the conductor strips. As here shown, the block 38 is provided with recesses 38, 48, 4| in a longitudinal face thereof, and apertures are provided in a longitudinal end thereof to provide for the entrance of the adjacent extremities of the conducting strips to within the respective recesses.

Recesses 42, as best shown in Figure 4, are provided in the opposite longitudinal end to permit energy source conductors to enter the recesses 38, 48, 4| formed in the block 38. a

The conducting strip 35 has an angular extremity 43 provided with an aperture to pass the shank of the terminal 2 a nut 44 being positioned on the screw-threaded shank to hold the conducting strip in operative position. The other extremity of the conducting strip 36 has its end doubled over upon itself, and the doubled over end passes through the aperture formed in one longitudinal end of the block 38 and is disposed in the recess 39. The doubled over end may be provided with a screw-threaded recess to provide for interengagement with a screw 45. A dish-shaped washer 46 is interposed between the head of the screw 45 and the doubled overend of the conducting strip 35, and provides means for engaging the bared extremity of an energy conductor 41.

As shown in Figure 2, the terminals 2 I, 22, and 23 are diametrically in line, the conducting strip 35 extending rectilinearly to the connection block 38. The conducting strip 36 is angular in longitudinal extent, and has a downwardly bent apertured extremity held to the terminal 22 by a nut the inwardly directed surfaces of the legs 68, 6|

and secured to the terminal 23 by a nut 52, and the other extremity having its end doubled over and passing through the aperture in one longitudinal end of the block 38 and disposed within the recess 4| formed in the block 38. The ex- 5 tremity within the block 38 is provided with av screw-threaded aperture to receive the shank of a screw 53. A dish-shaped washer 54 is interposed between the head of the screw 53 and the doubledover end of the conducting strip 31. to provide 10 means for the reception of the bared end of an energy conductor 55.

The support |4 may be provided with slots 56, formed at spaced points along its periphery, to prevent distortion which may result from differential expansion.

Referring particularly to Figure 6, the peripheral edge of the support I4 is here shown as provided with spaced-apart flattened integral lug portions 51, and the upper surface of the support l4, adjacent each lug portion 51, is provided with a recess 58 having a flat bottom wall angularly disposed with respect to the lug portion 51. Co-

operating with each lug portion 51, here shown to be three in number, are connection means 58, preferably in the form of a U-shaped clamp, having a short leg 68, a relatively long leg 6|, and a bight 62. Each' U-shaped clamp 58 is positioned to engage a respective lug portion 51, with 30 respectively frictionally engaging the flat bottom wall of the recess 58 and the flat bottom surface of the support 14, and the bight 62 of the clamp 59 abutting the flattened surface of the lug portion 51. The end of the leg 6| is provided with an angularly downturned projection 63, having its extremity reduced in width to provide a tongue 64. The bight 62 is provided with an inclined portion 65, intermediate the legs 68, 6|, the inclined portion 65, adjacent the leg 6 I, having a part struckout intermediate its width to form a shoulder.

With the clamps 59 in place on the support, reflecting means 61, having apertures 68 formed therein, are positioned so that the apertures 66 correspond with the tongues 64 of the clamps 58. The tongues 64 of the clamps 58 are formed to pass through the apertures 68 so that the shoulder, formed-between the reduced tongue and the downturned projection 63, will abut the adjacent surface of the reflecting means to space the reflecting means 61 from the heating element I8, and the portion of the tongues 64 extending through and away from the reflecting means is bent over the adjacent surface to hold the refleeting means in position." The reflecting means 55 61 may be metallic, preferably of heat-resisting material such as chromium, and is provided with a central aperture 69 to pass the center terminal 2|, and peripheral notches 18 and 1| to pass the terminals 22, 23. It will be appreciated that the connection of the strip conductors 35, 36, 31, to their respective terminals, cannot be effected until the reflecting means 61 has beenproperly as-- sembled with the support H. To provide passage for the heat transmitted by the reflecting means, the support |4 may be provided with axially ex-' tending apertures throughout its area, two of such apertures, 12 being shown in Figure 3. -The reflecting means may also be provided with a conductor receiving means, such as a screw I3, threaded into a screw-threaded aperture in the reflecting means, to provide for a connection to a suitable ground, to obviate danger resulting from short circuits.

The adapter ring II is preferably formed as 1 disclosed in Figures 3 and 6, wherein the ring I I is shown to be of annular U-shaped construction, with the outer annular flange .14 being shorter in axial extent than the inner annular flange 15, So that when the flange 14 has its terminating surface abutting a surface of the recess I2 in the stove I3, the bight portion 16 of the adapter ring II and the top of the support I4 will, lie substantially in a plane including the top of the stove I3. The flange 15 of the adapter ring I I is provided with apertures 11, spaced apart to align with the connection clamps 59. To assemble the adapter ring II with the support I4, the ring II is disposed about the periphery of the support I4, with the inner surface of the flange I5 circumscribing the adjacent surface of the bight portions 62 of the clamps 59. Pressure upon the ring II will cause the inclined surface 65 of the bight portions 62 to cam the flange I5 radially outwardly, and further pressure will move the ring relatively and axially with respect to the support I4 until the margins of the apertures I1 in the flange 15 clear the shoulders 66 formed on the clamps 59, whereupon the surfaces adjacent the apertures l 1 will snap into engagement with the shoulders 66 and the inclined surfaces 65 and lock the adapter ring II in position.

Figure '7 discloses a diagrammatic electrical hook-up for the coils 24, 25. As here shown, the conductor 41 leads to the center terminal 2|, and the conductors 5|, 55 lead to the terminals 22, 23 respectively. If desired, current control means I8 and 19 may be respectively interposed in the conductors 5|, 55 to selectively control the energization' of the coils 24, 25. Therefore, it will be apparent that a low heat and a high heat may be established by the electric unit III by suitably manipulating the control means 18, I9. Furthermore, either a low or high heat may be maintained without the need of localizing the heat, it being appreciated that each of the coils 24, 25 traverses a considerable portion of the area defined by the periphery of the support I4.

It will of course be obvious that further changes in the heating qualities of the coils 24, 25 may be effected, as for instance, by using coils of different resistances, or by placing an additional current impeding device (not shown) in circuit with either one of the conductors 5|, 55 to supply current of different quantities to the coils 24, 25. Also, it is possible to directly supply the conductors 5|, 55 with current of different values, in which case it is preferable to provide two center terminals, each connected to a respective inner extremity of a coil, and returning to its respective circuit.

It will further be obvious that the coils 24, 25 may be formed of a single element of electric resistance and heating qualities, as for instance an element starting from the terminal 22, connected to the terminal 2|, and terminating at the terminal 23.

From the foregoing it will be apparentto those skilled in the art that the illustrated embodiment of our invention provides a new and improved heating means and accordingly, accomplishes at least the principal object of our invention. It further will be obvious to those skilled in the art that the illustrated embodiment of our invention may be variously changed and modified without departing from the spirit of our invention, or sacrificing all of the advantages thereof, and that accordingly, the disclosure herein is illustrative only, and our invention is not limited thereto.

- the bottom of a respective one of said surface recesses, and another jaw engaging said other surface, said jaws being connected by a part overlying the periphery of said body, and each of said clamps having also a portion connected to said member.

2. A heating device, comprising: a body, foimed of refractory material, and having spaced surfaces, said body carrying heating means; a heat directing member, overlying one of said surfaces, and having a plurality of recesses; and means supporting said member in position overlying said surface, comprising a plurality of metallic U-shaped clamps secured to said body at spaced points, the legs of each clamp engaging said spaced surfaces, and the leg engaging said one surfacehaving an extending portion, the extremity of which is reduced to form a shoulder and a tongue, and the bight of each clamp overlies the periphery of said body and is formed with an abutment; each of said tongues passing through the respective one of said member recesses, and being bent to overlie one side of said member, the other side of said member being clamped against said shoulders; and an adapter member, having aresiliently-distortable wall generally circumscribing the periphery of said body, said wall having recesses spaced to correspond to the spacing of the abutments of said clamps, and the marginal surfaces of said wall recesses receiving said clamp abutments in latching relation, the resiliency of said wall yieldably holding said abutments and the marginal surfaces of said wall recesses in such latching relation.

3. A heating device, comprising: a body, carrying heating means, and having spaced surfaces; a heat directing member, overlying one of said surfaces; means supporting said member in position overlying said one surface, comprising a plurality of clamps secured to said body at spaced points, each clamp comprising a portion embracing a peripheral part of said body and a portion connected to said member; and an adapter, for supporting said device; said adapter and each of said clamps comprising a snap-connection detachably connecting said clamp to said adapter.

4. A heating device, comprising: a body, carrying heating means, and having spaced surfaces; 2. heat directing member, overlying one of said surfaces; means supporting said member in position overlying said one surface, comprising a plurality of clamps secured to said body at spaced points, each clamp comprising a portion embracing a peripheral part of said body and a portion connected'to said member, each of said embracing portions having a wedge-shaped abutment extending beyond the periphery of said body; an adapter member, having a resiliently-distortable wail generally circumscribing the periphery of said body, said wall having apertures adapted to receive corresponding wedge-shaped abutments; said adapter member being assembled with said body by pressing said well over the incline oi saidwedge-shaped abutments, said abutments distorting said wall until said abutments snap into corresponding apertures, the resiliency of said wall yieldably holding said adapter member against disassembly from said body.

5. A heating device, comprising: a body,carrying heating means, and having spaced surfaces; a heat directing member, overlying one of said surfaces, and having spaced-apart apertures; and a plurality of spaced-apart clamp means, each having spaced portions engaging said body inwardly of the peripheral edge of said body and a part overlying said peripheral edge and joining said spaced portions; and each of said clamp means having a portion extending away from said one surface, the extremity of said extending portion being reduced, providing a shoulder and tongue; said tongues passing through respective apertures in said heat directing member, and being bent to overlie one side of said directing member, and said shoulders engaging the opposite side of said member.

6. A heating device, comprising: a body, carrying heating means, and having spaced surfaces; a heat directing member, overlying one of said surfaces; and a plurality of spaced-apart clamp means, each having spaced portions engaging said body inwardly of the peripheral edge of said body and a part overlying said peripheral edge and joining said spaced portions; and each of said clamp means having a connection with said heat directing member, holding said member in overlying position with respect to said one surface, and holding also said clamp means against disassembly from said body.

7. A heating device, comprising: a body, carrying heating means, and having spaced surfaces; a heat directing member, overlying one of said surfaces, and having a plurality of spaced-apart apertures; and a plurality of clamp means, spaced-apart to correspond to the spacing of the apertures in said heat directing member, each clamp means having spaced portions engaging said body inwardly of the peripheral edge of said body and a part overlying said peripheral edge and joining said spaced portions; and each of said clamp means having also an extending portion extending through a corresponding aperture in said directing member and formed to hold said directing member in position overlying said one surface, said extending portions abutting the marginal surface of corresponding apertures, holding said clamp means against disassembly from said body.

EDWIN L. WIEGAND. ERNEST N. CALHOUN. 

